JPH04259578A - Paper pressure contact mechanism in printer device - Google Patents

Abstract

PURPOSE:To obtain a uniformly printed surface without stripe-form density irregularities to improve printing properties by providing a leaf spring-form guide member which brings paper into pressure contact with a platen roller at its smooth surface having a coefficient of friction smaller than that of the surface of the platen roller. CONSTITUTION:A leading end 1a of paper 1 is clamped by a clamper 2, and the paper 1 is wound on a platen roller 3 to be printed. Upon completion of printing, a trailing end 1b of the paper 1 is brought into pressure contact with the platen roller 3 by a paper presser leaf spring 11, thereby being tightly wound on the platen roller 3. Therefore, the paper is prevented from levitating during printing, and a uniform printing without unevenness can be realized. Because the leaf spring 11 has a smooth surface, a trouble never occurs when the paper is fed to be discharged.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper pressure bonding mechanism for winding paper around a platen roller in a thermal transfer printer or the like.

0002

2. Description of the Related Art A conventional example is shown in FIGS. 3 to 6 using a general thermal transfer printer as a model. Figure 3 is paper 1
This figure shows the state in which the leading end portion 1a of the printer is clamped by the clamper 2 and wrapped around the platen roller 3 to start printing. At this time, as the cam 6 driven by the cam motor 5 rotates, the head holder 40
moves around the shaft 40a, and the thermal head 4 narrows the ink sheet 7 and is pressed onto the paper 1. In this state, printing is performed by causing the thermal head 4 to generate heat and rotating the platen roller 3 counterclockwise while winding up the ink sheet 7 in the A direction.

FIG. 4 shows the cam motor 5 after printing is completed.
The cam 6 is rotated to release the thermal head 4 from the platen roller 3, and the platen roller 3 is rotated to the print start position shown in FIG. 3 while the paper 1 is being clamped. At this position, by rotating the clamper 2 about the clamper shaft 2a from the position shown by the broken line to the position shown by the solid line, the leading end 1a of the paper 1 is separated from the clamper 2, and the clamping of the paper 1 to the platen roller 3 is released. When the platen roller 3 is further rotated counterclockwise from this state, as shown in FIG. Therefore, the leading end 1a of the paper 1 advances in the direction of the paper ejection roller 10 which rotates counterclockwise, and the paper 1 is ejected out of the apparatus.

0004

As shown in FIG. 6, when the trailing edge 1b of the paper 1 comes off the pressure roller 9 during printing, a phenomenon occurs in which it jumps from the state shown by the broken line to the state 1b' shown by the solid line. For this reason, there is a drawback that the pressure contact state of the head 4 changes during printing, resulting in streak-like density unevenness on the printed surface.

[0005]

[Means for Solving the Problems] In order to eliminate the above-mentioned drawbacks, the present invention provides a printer device that clamps the leading edge of paper to a platen roller and wraps the paper around the platen roller to perform printing, which has a friction coefficient lower than that of the surface of the platen roller. The apparatus is characterized by having a leaf spring-like guide member that presses the paper against the platen roller with a small smooth surface.

[0006]

[Operation] Pressing paper using a leaf spring has the advantage of space in that it can hold the paper much closer to the head than when using a pressure roller, so it can press the paper toward the platen roller even at the position at the end of printing. The paper does not fly up during printing. Furthermore, since the surface is smooth, there is no problem in paper conveyance during paper ejection.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a state in which the leading edge 1a of a sheet of paper 1 is clamped by a clamper 2, the sheet of paper 1 is wound around a platen roller 3, printing is performed, and printing is completed.

At this time, the trailing edge 1b of the paper 1 is pressed against the platen roller 3 by the paper presser plate spring 11, and the paper 1 is neatly wound around the platen roller 3, so that uniform printing without unevenness can be achieved. .

As shown in FIG. 2, as in the conventional example, by performing a clamp release operation at the print start position and rotating the platen roller 3 counterclockwise, the surface of the paper presser plate spring 11 on the platen roller 3 side is removed. has a surface that is sufficiently smooth and has a small coefficient of friction compared to the platen roller, so the paper 1 advances in the direction of the paper ejection roller 10 and is ejected out of the apparatus.

0010

Effects of the Invention As described above, the present invention provides a printer device that clamps the leading edge of paper to a platen roller and wraps the paper around the platen roller to print. Since the printer is characterized by having a leaf spring-like guide member that presses the platen roller against the platen roller, a uniform printing surface without streak-like density unevenness can be obtained, thereby improving printing performance. In addition, since the pressure roller can be eliminated, the number of parts is reduced and costs are reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a print completion state of a printer device according to the present invention.

FIG. 2 is a schematic configuration diagram showing a paper discharge state of the printer device according to the present invention.

FIG. 3 is a schematic configuration diagram showing a state in which a conventional printer device starts printing.

FIG. 4 is a schematic configuration diagram showing a print completion state of a conventional printer device.

FIG. 5 is a schematic configuration diagram showing a paper discharge state of a conventional printer device.

FIG. 6 is a schematic configuration diagram showing a state of a conventional printer device during printing.

[Explanation of symbols]

1 Paper 2 Clamper 3 Platen roller 4 Thermal head 5 Cam motor 6 Cam 7 Ink sheet 10 Paper ejection roller 11 Paper presser plate spring

Claims (1)

[Claims] 1. In a printer device that clamps the leading edge of paper to a platen roller and wraps the paper around the platen roller to perform printing, a leaf spring that presses the paper against the platen roller on a smooth surface with a lower coefficient of friction than the surface of the platen roller. A paper pressure bonding mechanism for a printer device, comprising a guide member having a shape.